Solid state storage in the form of flash based Solid State Drives (SSD) and solid state Peripheral Component Interconnect Express (PCIe) cards may provide higher performance than Hard Disk Drives (HDD), but may have a higher financial cost per unit of stored data. Similarly, high performance hard drives are typically more expensive per unit of stored data than high capacity hard drives. The performance of some applications may be improved if certain portions of data are stored in media having lower latency and providing faster access. For instance, in applications utilized for data mining, index information may be stored in fixed locations within specific storage volumes.
One way to accelerate access to data in a storage system is to utilize a cache. One type of cache stores frequently utilized data in Dynamic Random Access Memory (DRAM) in order to provide higher performance for data accesses. However, little distinction is made between different types of data, and most data passing through the system is cached. Because important data is processed along with less important data, important data is frequently cycled out of the cache. Further, because DRAM cache is expensive, only small amounts of data may be cached.